Pool heater blowing breaker

[Ctwxman]

Hi folks,
New to this forum but I'm excited to see what it has to offer. I'm in the process of winterizing my in ground pool for the first time (second season since the build but I'm doing the work myself). I have a pentair 1.5 up whisperflo pump and a Mastertemp 250k btu propane heater set up to a timer. To make a long story short, I've never had an issue and I shut the breaker off about 2 weeks ago to start turning everything off. Today I turned it on so I could run the pump and drain the pool down some and the breaker tripped. It continues to trip every time I put the switch on for the heater and pump. I isolated the pump and put the breaker back on and it started pumping. I then isolated the heater only, turned it on and boom. Breaker pops off again. So I know it's the heater that's causing this. FYI, it has run with no issues for 2 seasons and the heater runs with propane. Any idea what the heck could be the issue? I check to see if a wire was loose, for corrosion,etc and nothing!

 

[Ctwxman]

FYI, breaker is a 40 amp 220v breaker.

 

[ajw22]

Welcome to TFP.

Is the breaker GFCI?

You have a multimeter to check electrical within the heater?

Please create your signature and give us details of your pool.

 

[Ctwxman]

The breaker is a GFCI, and I do have a multimeter but I'm not sure where exactly to be checking. Hopefully my signature shows up here!
-Sam

 

[ajw22]

Is your heater the only thing on that breaker?

It is more likely a GFCI trip then an over current fault. GFCI trips are hard to find. You have to go through a process of elimination. First place I would look carefully is at the blower and see if you can disconnect it and see if the GFCI trips.

Manual is here --> http://www.pentairpoolme.com/uploads/document/file/554/Manual_MasterTemp.pdf See page 31 for wiring diagram.

 

[Ctwxman]

It's just very strange that everything has worked with no issue and then I kill the breaker and it suddenly doesn't work. I did wire nut off the whole heater and tried just the pump and it worked. The pool was completed in May, 2018 so I wonder if it's still under warranty. Unfortunately I have been unsuccessful in getting in tough with the pool builder to inquire about it. Is it possible that it could be the connections a little wet on the mechanical time switch and that's what's causing the gfi to trip? I'm hesitant to want to start opening up the heater and pulling wires apart before I isolate every other issue it could possibly be.

 

[ajw22]

If power runs though the timer I would look there first. Wire nut together the LINE and LOAD wires and bypass the timer.

 

[Ctwxman]

Power does run through the timer. I'll check it out in the AM. Thank you.